Antidepressants used to treat adults can calm kids with anxiety disorders. What are the risks?

News last week that a drug widely prescribed for depressed adults had been tested on children with severe anxiety disorders set off a spirited debate. Drug researchers were delighted by the positive results. Critics were aghast that mind-altering chemicals were being given to kids. Parents weren't sure what to think.

It's a tricky issue. Let's start by defining a few terms. Every child has his share of worries--those first-day-of-school jitters, shyness around strangers, fear of dogs or Ferris wheels. But severe social anxieties, which afflict 5% to 10% of children, are something else. These kids have anxieties that far exceed normal...